从 ASP.NET Core 后端调用 solvethree

// CaptchaClient.cs; .NET 8+, System.Net.Http.Json and System.Text.Json.Nodes.
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json.Nodes;

public sealed class CaptchaClient(HttpClient http)
{
    public async Task<JsonObject> CreateAsync(string site, string proxy, string requestId,
        CancellationToken cancellationToken)
    {
        using var response = await http.PostAsJsonAsync("tasks?waitMs=0",
            new { site, action = "login", proxy, requestId }, cancellationToken);
        response.EnsureSuccessStatusCode();
        return (await response.Content.ReadFromJsonAsync<JsonObject>(cancellationToken))!;
    }
    public async Task<JsonObject> GetAsync(string id, CancellationToken cancellationToken)
    {
        using var response = await http.GetAsync("tasks/" + Uri.EscapeDataString(id) + "?waitMs=15000",
            cancellationToken);
        response.EnsureSuccessStatusCode();
        return (await response.Content.ReadFromJsonAsync<JsonObject>(cancellationToken))!;
    }
}
// Program.cs, before builder.Build(), in an existing authenticated ASP.NET app:
// builder.Services.AddHttpClient<CaptchaClient>(http => {
//     http.BaseAddress = new Uri("https://api.solvethree.com/v1/");
//     http.Timeout = TimeSpan.FromSeconds(25);
//     http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
//         "Bearer", builder.Configuration["SOLVETHREE_API_KEY"]
//             ?? throw new InvalidOperationException("Missing API key"));
// }).ConfigurePrimaryHttpMessageHandler(() => new HttpClientHandler {
//     AllowAutoRedirect = false
// });
// Inject CaptchaClient into your authenticated controller/service. Pass its
// cancellation token, create once, save id and poll GetAsync with a finite deadline.